


Fall deeper and deeper, the sirens are singing your songs

by LightningZBolt



Category: Bring Me The Horizon, Sleeping With Sirens
Genre: Anal Sex, Bathtubs, Drunkenness, Established Relationship, Interspecies, M/M, Prehensile Penis, Shapeshifting, Sirens
Language: English
Status: Completed
Published: 2019-10-15
Updated: 2019-10-15
Packaged: 2020-12-16 19:47:21
Rating: Explicit
Warnings: No Archive Warnings Apply
Chapters: 1
Words: 5,815
Publisher: archiveofourown.org
Story URL: https://archiveofourown.org/works/21041771
Author URL: https://archiveofourown.org/users/LightningZBolt/pseuds/LightningZBolt
Summary: In the first visit Kellin makes to Oliver's house, Oliver learns something about him that he never would have expected, something fishy.





	Fall deeper and deeper, the sirens are singing your songs

**Author's Note:**

> I was surprised no one wrote a fic yet of Kellin being a literal siren, or maybe someone has and I just never saw it or it was never tagged, regardless, it had to be done.
> 
> Despite my enthusiasm, I kinda faltered a bit near the end, around mid-sex scene, I got stuck for nearly two weeks. Oh well, hope it isn't that bad. I even managed to not have piss this time! Well, for the most part. Maybe more than two people will read it now, hah. I could have fleshed out more of the details and mechanics, but I honestly just got so burnt out, I didn't do as much as I'd wanted to, maybe I'll do more of this in the future.
> 
> Expect more monstery stuff in the future as I love it.
> 
> See the end for some more info and pics.

A knock at the door triggers Oliver to get up from the couch nearby to greet who should be there. “Hi-” He gets wrapped into a tight hug as soon as he opens the door. “-Kellin.”

“Hello, Oli~” Kellin squeezes Oliver tightly. “It’s been forever since I’ve been able to touch you!”

“It’s been three weeks!” Oliver remarks, attempting to break out of Kellin’s grip.

“Three weeks too long!”

Oliver manages to pull himself out of Kellin’s arms. “Okay okay, I get it. There’s more than enough of me to last the week, don’t wear me out all at once.”

“Okay.” Kellin says. “By the way, it’s really hot outside. I don’t know how you deal with it.”

“What? No it’s not. It’s only 15.” Oliver says. “This is pretty normal.”

“Oh that sounds really cold.”

“No it’s not, I ain’t using your stupid format.”

“Oh, right. Uhhh. I don’t know how to convert them, but I swear it’s really hot.”

“Uh huh.” Oliver pushes past Kellin to check outside. It’s not hot, it’s not cold. “You’re just being a baby. It rains like every other day here.”

“Did it rain yesterday?”

“Yes.”

“Damnit, if the plane didn’t get held back a day I would have been here yesterday.” Kellin remarks.

“Okay?” Oliver questions. “What does that does matter?”

Kellin stares blankly in response. “So how was your day?”

“Boring. I filled out forms.”

“Oh. Okay.” Kellin walks over to the couch and sits down. “It’s just been a long trip.”

Oliver sits next to him. “Now you know how I feel.”

“At least I’m not sick.” Kellin says. He expects Oliver to answer him with snark, but instead, Oliver is...sniffing him. “...What are you doing?”

“You smell like...fish.” Oliver says with a glare. “Why?”

“...I was hungry and they had nothing else to eat but seafood?” Kellin answers like a question.

“Why would you willingly eat anything like that? Why would anyone for that matter?” Oliver questions with a hint of anger.

“I don’t know, It was, fine, I guess.” Kellin shifts on the couch away from Oliver, although he can only move a few centimeters into the arm.

“You should go shower because you make me puke.” Oliver remarks, faking gagging.

“Where’d that be?”

“In my room.”

“And where’s that?”

“Upstairs.”

“...And that is?”

“...Upstairs.”

“...I’ll go look around.” Kellin gets up with a sigh.

“You do that.” Oliver takes advantage of the extra space on the couch and lies on his back, relaxing. He finds himself drifting off to sleep after a short while.

~~~~~

Oliver wakes up some unknown point in time later. He thought it was because Kellin came back at first, but no, he’s still gone, he just woke up by himself. He sits up on the couch and stretches, yawning. His neck feels sore. He couldn’t have been asleep that long, it doesn’t take more than twenty minutes to shower. Maybe Kellin got lost, somehow, but he’s not that dumb.

He thinks he should go look for him, but he’s not sure it’s worth getting up for. Despite that, the need to pee makes him get up anyway. He expects to either bump into Kellin wandering around like a lost puppy or to hear the water running in the shower, but neither of those happen. The bathroom seems eerily empty when he walks in, yet the shower curtain is closed. “Kellin? Are you still taking a shower?”

“Yes.” Kellin responds from behind the curtain.

“How? It’s been, like, uhhhh. I don’t know how long. I fell asleep.” Oliver says.

“Can you give me a few minutes?” Kellin asks.

“Why? I’m just gonna pee, I’ll be gone before you even notice.”

“No, I really think you should just come back.” Kellin says.

“Why, embarrassed to be naked in the same room as me?” Oliver questions. “Your dick has been in my ass and mine has been in yours, what does being in the shower bring that’s somehow worse.”

“That has nothing to do with it!” Kellin says.

“Okay, then what is it?”

“Nothing, just give me a minute.”

“Are you wanking off?”

“No, I’m not.”

“Okay, then, so what?”

“Can’t you just, leave for two minutes, please?”

“No, this is my house, my bathroom, my shower, I can do whatever I want.” Oliver pulls open the shower curtain. What he sees is, well, not what he expected, Kellin is there, yes, but he’s laying on his back in the water in the bathtub and appears to be wearing a costume, a mermaid costume. “Okay what is this weird mermaid fetish thing you’ve got going on.”

Kellin stares up at Oliver with a frown. “I can explain, it’s not what you think.”

“Okay, I’m listening.” Oliver says.

“I-” Kellin stops talking as he doesn’t know how to word it.

“I can wait.” Oliver leans against the nearby wall, folding his arms and staring at Kellin.  
“You’re not gonna leave until you get an answer, are you?”

“Nope.”

“Right…” Kellin sighs. He runs a hand through his hair, revealing webbed fingers. He uses this unintended reveal to help him explain. “These.” He holds his hand out and points to his fingers with his other hand. “These are real.”

“Real stupid looking.” Oliver remarks.

Kellin whimpers. “That’s mean.”

“It’s a costume, who cares, I’ve worn a Sonic The Hedgehog costume once, more than once, danced in it. You can call it stupid, I still liked it.” Oliver says.

“It’s not a costume!” Kellin shouts.

“Okay, makeup then, and don’t act like that’s me mocking makeup or anything, I like wearing makeup.”

“It’s not a costume, it’s not makeup, it’s real. Real real real.”

“Okay so, you’re a furry then?”

“No, I-”

“It’s nothing to be ashamed of, I have a fursona too. He’s a fox.” Oliver remarks.

“...You do?”

Oliver bites his lip, he wishes he didn’t say that now. “I didn’t say anything.”

Kellin stares blankly. “Oliver, touch my tail.”

“Why?”

“So you can feel how real it is.”

“I don’t approve of making clothes out of animals.”

“It’s not a cost- Oliver, just touch my damn tail.”

“Alright, fine, chill.” Oliver steps forward and slowly reaches an arm out towards ‘Kellin’s tail’. He expects to feel some cheap shiny fabric, but it actually feels like...scales. The feeling makes him reel back and pull his hand away. “What the fuck.” 

He actually glances over Kellin’s entire body now, not only does he have webbed fingers and a fish tail, his skin looks purple tinted, he has scales going up his chest, gills on his neck, his pupils resemble more that of a snake’s, his ears even look like fins. He had dismissed all of these points as ‘a costume’ earlier, but now that he’s aware of the ‘realness’ of it all, he’s rather shocked.

“I told you! It’s real! It’s all real! Webbed fingers, fish tail, gills, fins, even my teeth, all different!” Kellin sighs with obvious distress.

Oliver feels conflicted, he kind of wants to just run out of the room and expect this moment to just be a fever dream and everything to go back to normal, but he also doesn’t want to look like a coward. He’d be a bad partner if he just bailed like that. “I don’t know what to say.”

“I don’t expect you to.” Kellin absentmindedly waves his hand in the water. “I’m not a mermaid though, I’m a siren.”

“Siren, siren, that sounds familiar…” Oliver remarks, pondering the word. It takes him a moment to figure it out, and when he does, he rolls his eyes and groans. “Sleeping With Sirens, Siren, seriously?! That was why!? REALLY?!”

“...Yes.” Kellin answers in a quiet voice.

Oliver covers his face with his hands and sighs loudly. “This is my life now.”

“Well, technically, it’s always been your life. You just now know something else about me.”

“What’s next?” Oliver asks, putting his hands down. “You’re gonna reveal to me that you’re actually an alien from another dimension?”

“No, but I am actually from the ocean, kinda, sorta. I can explain that too.”

“How about not. I’m getting real tired of this now.”

“C’mon, Oliver, I want you to at least understand a little more before you judg-” Kellin notices Oliver unzipping the fly of his pants while facing the bathtub. “...What are you doing?”

“I came in here cause I had to pee, what do you think I’m gonna do?”

“But there’s a…not here...I- Don’t!”

“You’ve never freaked out before.”

“I’m clean!” Kellin freaks out, quickly shapeshifting back into a human, jumping out of the bathtub, and running out of the bathroom.

Oliver chuckles, his plan worked.

Kellin shakes the dripping water off of himself and tosses on the first set of clothes he sees. Not the smartest idea as he’s still rather wet and Oliver will probably yell at him for getting his clothes wet, but...There is no but, that was really stupid.

“What are you doing?” Oliver asks, walking into the room. “You’re jittering around more than me when I’m off my meds.”

“I put on some random clothes of yours without drying off.” Kellin explains. “I promise, I won’t drip water on your Sonic comics.”

“I’m pretty sure you couldn’t anyway, they’re under my bed.” Oliver says.

“I...didn’t know those even existed, or that you even had any.”

“I do. Collected a bunch as a kid, collected more of a different series as an adult still do.” Oliver says, walking over to the bed. He gestures for Kellin to walk up to him. He reaches under the bed and pulls out a box. “Take a look.” He hands the box to Kellin.

Kellin struggles to hold the box up. “It’s really...heavy…” His arms hang down and he drops the box on the floor as he falls with it, laying over the box and breathing heavily from exhaustion.

Oliver slaps his forehead. “I forgot you were a twig.”

“I’m sorry.” Kellin pants. “I’m bad at this.”

“Well, you get my point at least.” Oliver grabs Kellin’s arm and pulls him up, then kicks the box back under the bed within the same movement. “I’m not a wimp like you.”

“And that’s why I fell in love with you~” Kellin remarks.

“Cute.” Oliver says in a flat tone. He pushes Kellin onto the bed. “Now get back to topic.”

Kellin bounces into a seated position. “What topic?”

“Don’t play dumb with me, you know, all that shit in the bathroom.” Oliver holds his hand up in front of Kellin’s face. “Like with the fingers.”

Kellin is mildly distracted by the “High Five?” tattoo on Oliver’s palm. “Oh, right.” Kellin frowns. “That thing.”

“Uh huh. Tell me, Kellin, how am I dating a FISH?” Oliver holds his arms in frustration

“Because you didn’t know I was?”

“No I mean, how are YOU a fish?”

“Well not technically a FISH, a siren.”

“You have a fish tail, scales, gills, you’re a fish.”

“Okay, fine, I’m a fish.” kellin says.

“How are you a fish!” Oliver shouts.

“I was...born...as one?”

“Why do you sound unsure?”

“Because I don’t actually know if I was born in that form or this form.”

“How would you not know?”

“Do you know what you did when you were first born? No, because you were too young.”

“Well surely if you were born with a FISH TAIL, people would freak out, and you’d find out.” Oliver explains.

“Well, sure, but, what if that DID happen, and everyone hid it from me?” Kellin remarks.

“Then tell me this, when did YOU learn you were a fish, and how did you learn what that meant.”

“Sounds cliche, so don’t judge, but, puberty. One night when I was 13 and taking a bath, I was, uhh...I was…” Kellin trails off.

Oliver raises an eyebrow.

“I was... touching myself…”

Oliver rolls his eyes.

“And when I...came...that came...with…” Kellin sighs. He feels so awkward. “It came with, involuntary shapeshifting, and I opened my eyes to a fish tail and webbed fingers and freaked out, very loudly apparently as my mom thought I was drowning.”

“Uh huh.” Oliver gestures for Kellin to get to the point.

“Well, anyway, my mom then explained to me what was going on. I thought she was joking at first, or that I was being punished for masturbating, but in fact, I was actually a siren, and being born to a human family, that didn’t show itself until I got older.” Kellin explains. “I also didn’t realize that the shapeshifting was controllable and I just had to think really hard about it and I could change forms voluntarily.”

“Okay, so that’s your origin story, but what’s the reason behind it, were your parents fish too?” Oliver asks,

“No, no one in my immediate family is.” Kellin says. “Well, actually my great uncle on my...mom’s side was a siren, I think, that’s what I was told anyway.”

“Or maybe that was a lie your mum told you to hide the fact that she fucked a fish before she had you.” Oliver says in an obviously joking tone.

Kellin looks visibly sad.

“I was kidding.”

“I know…” Kellin still looks sad.

“I swear, you better not fucking cry on me.”

“Oliver, I’m opening up about myself to you and you’re making jokes.”

“Well you’re a goddamned fish, do you want me to make jokes or do you want me to have an existential crisis about the fact that I’m dating a FUCKING FISH!”

“I’ve never told anyone else before.” Kellin says.

“Excuse me?!”

“I’ve never told anyone else what I really am, beyond my family who knew about it.”

“You didn’t ‘tell’ me, I just walked in on you.”

“Yes, but I did actually intend to tell you, at some point.” Kellin says. “I swear, I really did.”

“I don’t believe you, at all.” Oliver says in a stern tone. “In fact, you’re probably only saying that because you got caught.”

“That’s not true…” Kellin says in a quiet tone. “I really did want to tell you some day...I just hadn’t planned out how to…”

“Planned!? Why do you need to PLAN, you just fucking say it!”

“I didn’t want to be too hasty, I wasn’t sure if I had trusted you enough yet…”

“Oh, so you don’t trust me, is that it?” Oliver growls. “Well then I don’t trust YOU.”

“Oli no, that’s not what I mea-”

“No, you get out. I don’t wanna see your stupid FACE or hear your stupid VOICE until you give me a damn good reason for being so secretive.” Oliver demands in an angry tone. “I can’t believe I trusted you enough with my own issues and insecurities and you repay me by hiding your true self.”

“But, Oliver, I had good reason for i-”

“I told you to leave!” Oliver shouts. He threatens Kellin by holding up fists and leering at him.

Kellin gets up from the bed in a haste and runs out of the bedroom. He hears Oliver slam the door closed behind him. He stares down at the floor in sadness, not sure of what he should do. He can hear Oliver screaming in the bedroom, muffled by the closed door. He sighs and slowly walks into the bathroom across the hall to hide in. He sits on the (empty) bathtub floor and hides his face in his hands while he thinks about what to say.

~~~~~

Kellin hears the bathroom door open and Oliver walks in and up to the sink to wash his hands. He turns his head to glare at Kellin. Kellin shrinks down and hides behind the side of the bathtub until Oliver leaves. He sits back up and gets up, running downstairs as he doesn’t want Oliver to meet up with him again while still angry. 

He sits on the couch in the main room and lies down on his side, once again thinking about what to say. He feels this would be much easier if Oliver could just listen to him explain himself without getting irrationally angry. He’s never been good at emotional control, but he’s really bad right now.

~~~~~

Kellin’s thought process is interrupted when he sees Oliver walking past him to the nearby TV and picks up and video game controller. He flashes his middle finger at Kellin as he walks away with the controller in hand. Kellin frowns to himself. Oliver is still in a bad mood. 

Kellin sits up from the couch and walks to the kitchen to brainstorm, once again just to avoid him for longer.

~~~~~

Kellin is caught off guard from the sound of the fridge open as he was staring at his shoes. Oliver grabs a can out of the fridge and closes it with a slam. He leers at Kellin on his way back upstairs. Kellin sighs deeply. Oliver is never gonna calm down at this rate.

Kellin begins pacing the kitchen as he tries to get back on his train of thought.

~~~~~

Kellin gets a small glass of water from the sink as his throat feels dry from talking to himself for who knows how long now. He’s been thinking of what to tell Oliver, and he’s been failing at figuring out a solution. He feels at a loss. While drinking from the glass, he hears the sound of footsteps, along with a mutter of “fuck” followed right after what sounded like hitting a table. 

He turns to look in the direction of the sound and sees Oliver walking up to him...and past him to the sink. Oliver must have taken a wrong turn upstairs as he proceeds to retch and puke in the sink. He turns the faucet on and turns his head towards Kellin. “So, you wanna fuck or what?” He asks, his speech sounding slurred.

Kellin steps back in confusion and shakes his head.

“Oh, right.” Oliver grabs the half-full glass of water from Kellin’s hand and drinks the rest of it. He puts the glass down on the counter and turns the sink off. “Now?”

Kellin stares at Oliver with a confused expression. Oliver looks, tired? Sick? He doesn’t look angry at least.

“C’mon, mate, this is usually your thing, you go fucking mental for sex.” Oliver says.

“Yes, but this situation seems, bizarre.” Kellin responds.

“You’re a nutter.” Oliver says,

“I’m a what?” Kellin asks in confusion. He notices Oliver reaching for him and he backs off. “Are you feeling okay?”

“What are you talking about, I feel fine, better than fine.” Oliver says. “What would make you think otherwise? I can’t be forward and affectionate?”

“Not saying you CAN’T do that, it’s just a bit...out of character for you.” Kellin says.

“It’s out of character for me to be loving?” Oliver asks, sounding genuinely baffled. “I didn’t know that.”

“Well that and you sound drunk, very very drunk, and puking in sinks is a symptom of that. All that’s left is pissing yourself and passing out on the floor.” Kellin remarks.

“I bet you fifteen pounds that I can stay awake and away from floors and that I will not piss myself all night.” Oliver says.

“I can’t do anything with pounds, but, okay.” Kellin says.

“Okay, I’ll make it twenty pounds then.” Oliver adds, seemingly missing Kellin’s point.

“No it’s fine, you can keep your money.”

“Twenty five pounds.”

“Okay, sure, twenty five pounds. That’s like, thirty bucks maybe?”

“Deal made, now let’s snog.” Oliver reaches out for Kellin again.

“I don’t know what that means and I want nothing to do with it.” Kellin backs farther away. It sounds uncomfortable.

“It just means making out!” Oliver remarks. “Fuck’s sake.”

Kellin turns away from Oliver and runs to the stairs. He turns to watch Oliver follow him, slowly, with a stumbling gait, making sure he doesn’t somehow trip on his own feet or something. He resumes walking upstairs once Oliver gets close and waits for him in the bedroom. At least in there Oliver can’t hurt himself, maybe. Hopefully. He sits on the side of the bed.

Oliver stumbles into the bedroom and holds onto the door frame so he can keep himself up. “See, I’m just fine. You worried for nothing.”

“Said by the guy holding himself up by the door frame.” Kellin remarks.

“Ah shut up, what do you know.”

“The fact that you’re drunk.”

“And so what if I am? What does it matter?”

“It alters your behavior and mannerisms.”

“That’s a lot of big words.” Oliver says. He seems hesitant to move away from the door frame, but he eventually does, slowly, and nearly falls into bed, but catches himself before he does. “Alright, you wanna fuck now?”

Kellin shakes his head.

“Every other goddamned bloody time you’re the one begging me for sex, and the one time I ask first, you say no, what the fuck is your problem?”

“Did you happen to forget why I wasn’t with you for hours to begin with?” Kellin asks.

“I’m too shit-faced to remember anything that happened today.” Oliver says. “All I know is that you’re here and that my cock is scraping against my jeans begging for release.”

“I’d like to help you with that, I really would, but I really think we-”

“Then do it already.” Oliver interrupts Kellin and grabs his arm. “I don’t care what you do, just something.”

“...I think we should first talk about me.” Kellin says in a firm tone.

“Okay.” Oliver says, blissfully unaware of Kellin’s intent. “I think you’re cute, but you’d look even cuter with my dick in your mouth.”

“Thanks, and, I agree. But...Oliver, do you at least remember earlier, in the bathroom?”

“No, what happened?”

“You walked in on me in the bathtub.”

“I’ve seen you naked plenty of times.”

“I’m actually a siren!”

Oliver stares at Kellin in confusion.

Kellin sighs. “Look at me.” He closes his eyes and concentrates his mind, shapeshifting his body, causing his legs hanging off the bed to turn into a fish tail, his ears to turn into fins, and his hands to turn webbed. “This is me, this what I really am!”

Oliver releases his grip on Kellin’s arm while he stares at him with a wide-eyed look. His eyes follow his body down to his tailfin and then back up to his face. “I remember now…” His voice sounds somber in tone.

“I know now what I should have said, it was wrong of me to not trust you sooner, I’m sorry. I haven’t told anyone else I’m close to as I’m afraid of the secret slipping out publicly and then I’ll get focus on me for what I am instead of what I make. I don’t wanna be known as a fish who happens to make music, I wanna be known for my music first and foremost.” Kellin explains. “What I happen to be is inconsequential to all of this.”

“But why do you trust me and not anyone else?” Oliver asks. “You haven’t even known me for very long comparatively.”

“Because you’re so much more...blunt? Honest? You’re very good at keeping things things to yourself.” Kellin says. “You’re only as open as you need to be to those that matter.”

“Well I did manage to hide my gayness even from myself for years.” Oliver remarks. “Some friends you got then if I’m somehow a shining example of greatness. I don’t feel like I’m anything special.”

“But you are special.” Kellin says. “And I’m not saying anyone else is bad, I mean, Vic is really nice and all, but he’s not good at keeping things to himself. He’s shared every single thing I’ve told him not to before and I’d rather not take the risk with something this big. And then there’s-”

Oliver grabs Kellin a hug. “I forgive you for hiding, and I’m sorry for being angry earlier.”

“You remember you were angry at me?”

“Of course, it’s why I got sloshed, so I could forget.” Oliver says. “But you reminded me, and I really just wanna move past that now.”

“I forgive you too.” Kellin hugs back. “But I just have one more question, do you accept, and love me, for what I really am?”

“I’d still love you even if you told me you were actually a two thousand year old dragon.” Oliver says. “Cause honestly that’d be pretty cool. But a mermaid fish thing is almost as cool.”

“I’m glad to hear that.” Kellin smiles.

“Where do your clothes go when you transform?” Oliver asks.

Kellin’s expression goes blank. “I don’t know.” In those words, he takes it as a cue to shapeshift back into a human.

Oliver’s hands notice the texture shift from scales to fabric . He pulls away from the hug and sees that Kellin is indeed back to ‘normal’. “So how about we fuck now?”

Kellin is still caught off guard by Oliver being so blunt about this as he rarely ever is when sober. “Sure, we can fuck now.”

“Fucking finally.” Oliver unbuckles his belt and unzips the fly on his jeans, with a bit of a struggle as his motor skills are shaky in his drunken state. He manages to do it though, and pulls them down to let out his cock.

Kellin stares at Oliver’s cock with minor distraction, he notices that it’s throbbing, he clearly wasn’t kidding about ‘begging for release’. “Oh right.” He almost forgot to do the same and as soon as he snaps back to it, he unbuckles and pulls his own pants down, with far less struggling as he’s not intoxicated.

Oliver grabs Kellin and pushes him onto his back, kissing him as he does so. At the same time, his erection rubs itself against Kellin’s own.

Kellin breaks the kiss. “Do you wanna know another secret that isn’t really a secret but it’s secretlike?”

“Y-yes?” Oliver sounds confused. “Share away.”

“I don’t need to be in water to transform.” Kellin reveals.

“What does this chan-” Oliver gets cut off by Kellin grabbing his arms as he shapeshifts under him. At first, Oliver assumes this changes nothing truly significant, until he experiences what feels like a hand on his cock, but Kellin’s hands are on his arms...and then he glances down and realizes that shapeshifting changes Kellin’s dick too. It appears to be, moving on its own, stroking his own dick like a finger or a tongue.

“Pretty cool, huh?” Kellin asks.

Oliver is silent out of shock. He isn’t sure if he feels disturbed, disgusted, impressed, mesmerized, or what. A combination of all of those perhaps. The size hasn’t changed, but the shape has, it’s tapered now, and a lot...wetter.

“Ever seen a dolphin’s penis before?” Kellin asks.

“Uhhh, no?” Oliver answers.

“Well it’s kinda like that~” Kellin giggles. “It’s really fun to play with, and really wet~”

“I...noticed…” Oliver has settled on the emotion of ‘oh god what the fuck is this I hate it but don’t stop please’ if that can even be conveyed.

“Are you okay?” Kellin asks.

“What?”

“You look distressed.”

“Well yes I’m distressed, I’ve got a prehensile dick wanking me off.”

“Oh, do you want me to do something else instead?”

“I didn’t say tha-”

Kellin unwraps his dick off Oliver’s, snakes it past his balls towards his anus and slowly slides it inside him, the tapering shape and excessive wetness making it almost effortless.

“Kellin what are you doing!?” Oliver shouts. “I don’t like that, stop.” He begs.

“Do you really want me to stop?” Kellin asks.

“No, don’t stop…” Oliver whispers. He can feel every last shred of his dignity fading away, if he had any left to begin with. Why it took until getting buttfuckd by a fish for this to happen only makes sense to him.

“Okay then~” Kellin thrusts into Oliver using his tail to push against the bed and up as if he was swimming. “It’s just like swimming~”

“Ssssure… Ssswimiiing…” Oliver mumbles while drooling. His mind is foggy right now with feelings of positivity. Kellin’s siren dick is like a combination of a tongue and cock in his ass at the same time. It’s simultaneously bizarre, gross, and incredibly pleasurable.

“You know, since I never revealed my true self to anyone else before, I never did this with anyone else before either~” Kellin says. “Just myself~”

“Uh huh…” Oliver mumbles. He’s only paying attention to 15% of what Kellin said, ‘never’ and ‘myself’ and he just fills in the blanks that his ears didn’t listen to. Something about never touching himself or whatever. Sounds like a lie, that’s almost all he ever does.

“Are you okay? Like, you don’t usually like this stuff as much as me.” Kellin asks.

“Would you shut up.” Oliver demands. “You worry about everything.”

“Sorry…” Kellin apologizes. He focuses back on just the sex, the one thing he can’t mess up.

Oliver’s focus on words fades away again and he just tries to enjoy this, he’s still a bit weirded out by staring down at a Kellin with fins, but he’ll grow used to it. The fins are less weird than the dick anyway. Still, it’s hard to complain about it much because-

“Oli, are you listening?” Kellin’s question breaks Oliver’s lack of focus.

“What.” Oliver says.

“Did you want me to-” 

“What?” Oliver sees Kellin gripping tightly onto him while he feels something warm filling his ass. “Oh fuck. Why.” He’s never been fond of this feeling as he’s just not used to it.

“I’m sorry, you didn’t tell me not to…” Kellin says.

“Whyyyy.” Oliver whines.

“If you sit still, I can probably use the prehensibility of-”

“Please don’t describe to me the process of scooping jizz out of my ass with your freaky fish dick.”

“We talk about pleasant things together, don’t we?” Kellin says with a smile.

“Get your dick out of my ass already!” Oliver demands.

“Okay!” Kellin shoves Oliver off of him, forcing him off his dick onto the bed. “Are you happy now?”

“No.” Oliver says. “I’m not.” He sits up and crawls next to Kellin on the bed.

“Would it kill you to be nice for once? We can’t even have sex without you complaining and bickering.” Kellin says.

“Shut up you stupid fish.” Oliver grabs Kellin’s head and kisses him.

“That doesn’t make it okay.”

“Oh you know you like it.” Oliver kisses him again. “You wouldn’t be dating me if you didn’t.”

“Well are you okay with dating a ‘stupid fish’?” Kellin asks.

“I’m still here, aren’t I?” Oliver remarks. “I didn’t kick you out onto the street.” He lays on his side next to Kellin and rubs his cock on Kellin’s scales using his hand. “Plus I just think it’s kinda neat.”

“You don’t hate me?” Kellin asks, mildly distracted by Oliver rubbing his dick on his tail scales.

“Did we not go over this earlier?”

“I don’t remember.”

“I’m the one that should be saying that! I didn’t see you drinking.” Oliver says. “But no, I don’t hate you, I still love you.”

“Really?”

“Would I do this if I hated you?” Oliver supplements his words by cumming on Kellin’s scales.

“You might, if I didn’t like it.”

“But you do like it.”

“I do like it, yes.”

“Cockslut.” Oliver says with a smirk.

“Your insides feel nice.” Kellin says.

“...Thanks.”

“I’m only saying that as you don’t know what it’s like to have a prehensile penis.”

“I’m glad for that, and the more you explain this, the more I’m regretting saying I’m okay with you being a fish.”

“Well this conversation was already going downhill, couldn’t make it much worse by adding that too.” Kellin says.

“Uh huh.” Oliver sighs. “I’m gonna sleep now. Don’t get scales in my bed.” He rolls over onto his other side, fixes his clothes, and wraps up in a blanket.

“So mean.” Kellin remarks as he shapeshifts back into a person before getting up from bed to shower.

~~~~~

Oliver wakes up with an uncomfortable feeling, before he can react though, his nose is violated with a strong stench. “Fuck!” He holds his nose as he sits up in bed.

“What’s wrong?” Kellin asks, seemingly having been awake.

“It smells like I was balls deep in a swordfish.” Oliver gags. “Fuck.”

“Did you piss yourself?” Kellin asks.

“What? Maybe, but that doesn’t smell like FISH.”

“Well technically, I was balls deep into YOU, and technically I don’t have external balls as a siren, and most fish don’t have external-”

“I KNOW, It was a figure of speech.” Oliver shouts. “Fuck.” He gets up from bed. “I need to shower before I puke.”

“Sorry, I guess that’s just something you’ll have to get used to.”

“Great, I’ll have to get used to waking up smelling like rotting seafood.”

“At least I’m not actually rotting seafood?” Kellin grins.

Oliver sighs and rolls his eyes.

~~~~~

Later in the day, mirroring the day prior when Kellin first showed up, Oliver walks in on him again lounging in his bathtub with his tail partly sticking out. “Is this gonna happen all the time when you visit me?”

“It could happen when you visit me too.” Kellin says. “Are you piss in the water again?”

“No, I have another idea.” Oliver gets in the bathtub with Kellin, clothes and all, and hugs him, not really caring about the water getting everywhere.

“But why, you could at least take off your clothes first.” Kellin pushes against him so he doesn’t get shoved entirely underwater.

“This is supposed to be innocent.” Oliver kisses Kellin on the cheek. “And I wanted to apologize for being a dick yesterday and this morning.”

“You always are though, and it’s fine, I don’t mind it.”

“I shouldn’t be mean to you, you’ve been nothing but nice to me and have helped me with so much, the least I could do is be less of a dick.” Oliver pets his ear fins.

“I appreciate the apology, and I accept it. You don’t need to be in here with me though to say it.” Kellin says.

“But I want to, when else am I gonna find the excuse to pet a fish?” Oliver says.

“Are you gonna complain about fish smell later as a result of this?”

“Probably, but that’s future me’s problem.”

“Okay, but that means I have permission to bring up this conversation later if you do complain.” Kellin remarks.

“Yeah, sure.” Oliver kisses him.

Kellin kisses him back and hugs him. “What about the wet clothes, are you gonna complain about that too?”

“Shush, just let me love you.” Oliver hugs Kellin back tightly.

“Okay.” Kellin loosely drapes his tailfin up on Oliver’s back as they hug.

**Author's Note:**

> I based Kellin's details mostly on how I have depicted him in my Sims 4 game. Yes, I have a Kellin Sim, he's a mermaid, and an Oliver Sim, and yes they are married. I would be that person. Anyway, I thought mostly of how I designed him with the descriptions, but honestly if you wanna see him differently, you're free to do that as well. I just prefer more monstery.
> 
> Here's a few pics of him, both as a mermaid and human.  
[Mermaid](https://i.imgur.com/nmBUETu.png) [Human 1](https://i.imgur.com/776Yp2B.png) [Human 2](https://i.imgur.com/8wG47WI.png)
> 
> If you're curious to see my Oliver sim too.  
[Oliver 1](https://i.imgur.com/KqHHABU.png) [Oliver 2](https://i.imgur.com/PHwQ0RS.png)
> 
> And if you wanna see them together.  
[Human and mermaid 1](https://i.imgur.com/IDctkdi.png) [Human and mermaid 2](https://i.imgur.com/vdbxsmz.png) [Both humans 1](https://i.imgur.com/beI3sHl.png) [Both humans 2](https://i.imgur.com/BrNcT3e.png)


End file.
